Honestly, even I am a chinese, I can't understand his english. His english is more than accent. He can't pronounce a word correctly. And his curve is not generous at all. Avoid him if you could.

UCLA is all about trying to make itself seem like a diverse campus. One way they show this is through their hiring of professors. So many will have an accent. Song is one of them. Usually, you adapt to it, and maybe even enjoy it, but not with Song, unless you laugh at his grammatical/oral mistakes.. His accent is very hard to get past. I thought by now, I was a pro at understanding people, but boy was I wrong.

Song's lectures are the book, so going to lectures is not always efficient except for turning in homework on Fridays. Sometimes, he made errors, and the class would correct him, or even point out which page in the book he was miscopying from. Really guys. His lectures are close to pointless.

He is, however, lenient with homework. Like, he would ignore people turning in their homework in the middle of his lectures, and even accept it if you turned it in at the end of class after doing it during class. If you have a morning class with this guy, and you oversleep for various excuses, then you can drop off your homework in his office hours after class. Just say something like: "I forgot to turn it in, whoops.." Just to be on the safe side, don't just depend on turning in your homework after missing class, because he might get irritated if you keep showing up or something (just saying), although turning it in when he is in the classroom/building is perfectly fine. If you ever need homework help, find a buddy to compare answers with, ask your/a T.A., and try visiting the student math help center.

His T.A.'s or at least one of them, will be a great help. Go an check each of their sections out. Some will hold review sessions before the midterms and final, so that is pretty good. Just see which one you can learn with, and also remember to visit your official T.A. at least once in a while to, for the least, pick up homework or past midterms.(Covel Tutoring also helps, but if you can't get in, there is AAP and the Rieber Fireside Lounge drop-in tutoring.)

Speaking of which, his midterms are super do-able. He had a high curve for his first one, and so he thought he would try to make the second one harder. It's not the end of the world if you don't do well in these. They count for a small part of your grade, compared to the final.
The final is...your life. If you don't do well, or on the curve at least, expect somewhere around a B- or lower, depending on how low your final is and how your midterms turned out. Try out the test bank in the Student Activities Center, it might help. A good way to study is to redo homework problems, or try whatever types of problems you have covered in class in the Chapter Review. Also, you get a cheat sheet, so memorization is not an issue (if you write really small on that cheat sheet), it's just thinking and how to apply formulas/techniques (new or from the last midterm), into the problems.
Each exam has a bunch of questions, with the first composed of multiple parts for short answers usually. Check your answers if you have time.
So basically, for Math 31B, his lectures are win-or-lose (you might learn something, as if(joking), or you might be wasting precious (sleep) time), you be the judge. Try other professor lectures. His homework is simple and you shouldn't panic over it too much. Find a buddy, go to a discussion, find help if you need it in general, somehow. Study for midterms, and with a T.A. in review sessions. Study harder for the Final. I'm making his class sound a lot more difficult than it should be, but that still doesn't mean you should always underestimate it.. Alright then, good luck. :)

Ewwww. I would enroll in this class, but go to some other professor's lectures. This guy knows some math, but he sure can't teach it well enough... His midterms were a piece of cake, but his final was a %$#&@. Go to discussion sections, and maybe get some covel tutoring. Song is nice about hw thought, since you could go to his office hours and turn in the hw and still get full credit, assuming you did all of your work okay.

Accent: booo
Homework/midterms: woo
final: meh...

Everything that has been said about his accent is completely true. I remember the first time he spoke, my friends and I all turned to each other and started asking each other WTF is he saying! But after 3 weeks, you will slowly get accustomed to it and able to comprehend "most" of what he is saying. Once you are able to understand what he is saying, the problem is, he just isnt a very good teacher. He does make an effort to explain things if people are lost but not very clearly. The TAs on the other hand seem to do a much better job. My TA summarized everything that had been said in lecture, so discussion was much more beneficial than lecture. I stopped attending lecture for the last 5 weeks and just read the book since Song's examples and notes are straight out of the book anyway. Midterms are really easy so dont screwed up or the curve will eff you over. No quizes, only weekly hw assignments due on Friday. Final was quiet difficult.

Effectiveness: I completely agree with others on here about the communication gap. Being at UCLA, you get used to accents of all types from all over the world. And generally, you can get past them. Not with Song. Not at all.
Difficulty: If you can learn the material by reading the textbook or some other way (tutoring, TA office hours, etc.), then you shouldn't have a *problem* with Song's class. It just won't be as enriching as it can/should be. He lectures straight out of the book, assigns the easier homework problems, and allows you to have a cheat sheet on every test.
Overall: If you are fine with not being able to fully understand a single lecture and think you can learn the material yourself, you'll be fine with Song. Certainly not the best, but STILL better than C. Martin (Visiting Professor).